Head-to-head comparison across 3benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
GPT-5.4 Pro
91
Grok 4.20
73
Pick GPT-5.4 Pro if you want the stronger benchmark profile. Grok 4.20 only becomes the better choice if you want the cheaper token bill or you need the larger 2M context window.
Agentic
+42.2 difference
Reasoning
+30.0 difference
Multimodal
+23.2 difference
GPT-5.4 Pro
Grok 4.20
$30 / $180
$2 / $6
74 t/s
233 t/s
151.79s
10.33s
1.05M
2M
Pick GPT-5.4 Pro if you want the stronger benchmark profile. Grok 4.20 only becomes the better choice if you want the cheaper token bill or you need the larger 2M context window.
GPT-5.4 Pro is clearly ahead on the provisional aggregate, 91 to 73. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.4 Pro's sharpest advantage is in agentic, where it averages 89.3 against 47.1. The single biggest benchmark swing on the page is ARC-AGI-2, 83.3% to 53.3%.
GPT-5.4 Pro is also the more expensive model on tokens at $30.00 input / $180.00 output per 1M tokens, versus $2.00 input / $6.00 output per 1M tokens for Grok 4.20. That is roughly 30.0x on output cost alone. Grok 4.20 gives you the larger context window at 2M, compared with 1.05M for GPT-5.4 Pro.
GPT-5.4 Pro is ahead on BenchLM's provisional leaderboard, 91 to 73. The biggest single separator in this matchup is ARC-AGI-2, where the scores are 83.3% and 53.3%.
GPT-5.4 Pro has the edge for reasoning in this comparison, averaging 83.3 versus 53.3. Inside this category, ARC-AGI-2 is the benchmark that creates the most daylight between them.
GPT-5.4 Pro has the edge for agentic tasks in this comparison, averaging 89.3 versus 47.1. Grok 4.20 stays close enough that the answer can still flip depending on your workload.
GPT-5.4 Pro has the edge for multimodal and grounded tasks in this comparison, averaging 94 versus 70.8. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.
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